Effect of WC Mass Fraction on Friction-Wear Performance of Laser-Cladded Stellite-21-WC Coatings at High Temperature

WC-reinforced Stellite-21 coatings were prepared on AISI H13 steel by laser cladding (LC). The microstructure, phases and hardness of obtained coatings were analyzed by super-depth of field microscope (SDFM), X-ray diffraction (XRD) and microhardness tester, respectively. The effects of WC mass fraction on the coefficients of friction (COF) and wear rate of WC-reinforced Stellite-21 coatings at 550 °C were investigated. The results indicated that the undissolved WC particles act as the skeleton for the Stellite-21 coating, which has a positive effect on the improvement of hardness. The average COFs of Stellite-21-10%WC, Stellite-21-20%WC and Stellite-21-30%WC coatings are 0.447, 0.383 and 0.349, respectively, and the corresponding wear rates are 192.4, 148.6 and 101.4 μm3 N−1 mm−1, respectively, showing that the wear resistance increases with the increase in the WC mass fraction, and the wear mechanism is combined by the adhesive wear, abrasive wear and slight oxidative wear.